414 TROPICAL NATURE vI 
Homer’s time he had advanced to the imperfect discrimina- 
tion of red and yellow, but no further; the green of grass 
and foliage or the blue of the sky being never once referred to. 
These curious facts cannot, however, be held to prove so 
recent an origin for colour-sensations as they would at first 
sight appear to do, because we have seen that both flowers 
and fruits have become diversely coloured in adaptation to 
the visual powers of insects, birds, and mammals. Red 
being a very common colour of ripe fruits which attract birds 
to devour them and thus distribute their seeds, we may be 
sure that the contrast of red and green is to them very well 
marked. It is indeed just possible that birds may have a 
more advanced development of the colour-sense than mam- 
mals, because the teeth of the latter commonly grind up and 
destroy the seeds of the larger fruits and nuts which they 
devour, and which are not usually coloured ; but the irritat- 
ing effect of bright colours on some of them does not support 
this view. It seems most probable, therefore, that man’s 
perception of colour in the time of Homer was little if any 
inferior to what it is now, but that, owing to a variety of 
causes, no precise nomenclature of colours had become estab- 
lished. One of these causes probably was, that the colours 
of the objects of most importance, and those which were most 
frequently referred to in songs and poems, were uncertain 
and subject to variation. Blood was light or dark red, or 
when dry, blackish ; iron was gray or dark or rusty ; bronze 
was shining or dull; foliage was of all shades of yellow, 
green, or brown; and horses or cattle had no one distinctive 
colour. Other objects, as the sea, the sky, and wine, changed 
in tint according to the light, the time of day, and the mode 
of viewing them ; and thus colour, indicated at first by refer- 
ence to certain coloured objects, had no fixity. Things which 
had more definite and purer colours—as certain species of 
flowers, birds, and insects—were probably too insignificant or 
too much despised to serve as colour-terms; and even these 
often vary, either in the same or in allied species, in a manner 
which would render their use unsuitable. Colour-names, 
being abstractions, must always have been a late development 
in language, and their comparative unimportance in an early 
state of society and of the arts would still further retard their 
